Nice pics Snake and Sidious. Congrats.
On the left hand 'appearing to have flesh on it again' issue - personally I don't think the intention in the film was that he 'put it back on'. I think he left it off and that's why he bothered wearing the gloves. Now there are points in the film where you can see Arnie's wrist under the jacket sleeve but I think that's just a ''blooper'' so to speak.
Also when the arm eventually gets damaged at the steel mill the remaining arm is fleshless, which I think means it wasn't there since Dyson's house. (you could suggest that it ripped back off with the hand when he pulled free of the gears but I don't remember seeing anything suggesting that could be the case)
I would say putting blood and flesh on the left hand was an oversight by HT and it just never clicked with them. And yet they still knew to sculpt the BD arm with the flesh neatly cut away below the elbow.